Magnetic resonance imaging (MRI), or nuclear magnetic resonance imaging (NMRI), is primarily a noninvasive medical imaging technique used in radiology to visualize detailed internal structure and limited function of the body. MRI and NMRI devices are examples of a class of devices called magnetic response devices (MRD).
Objects to be analyzed are positioned within an MRI device in a predefined specific location and configuration. It is advantageous to adjust the location of the animal under inspection within the MRI device to obtain optimal analysis. Few patents pertain to means and methods of positioning analyzed objects. Hence for example, U.S. Pat. No. 5,066,915 discloses an RF coil positioning device tier an MRI device in which a pallet is movably mounted on a mount and is moved by a drive means so that an RF coil unit mounted on the pallet is moved from its initial position at an imaging position in a magnetostatic field generator. Likewise, US patent discloses a diagnostic table for a medical imaging apparatus. However, the MRI operator in those MRI systems cannot routinely, quickly and easily switch between one object to another, and between one type of object to other object.
Fine tuning of the various shape, size and type objects, especially in laboratory routine, wherein a frequent switching of scanned objects of different type shape and size is practically impossible utilizing those MRI systems. In addition, the magnetic field produced by the MRI magnets is sensitive to variability of the magnets originally occurring in the manufacturing process. It is also sensitive to the ambient temperature of the examination area. Therefore, the frequency of the magnetic field changes between one venue and another, and between one operation and the next, and even once in every few scanning procedures. Radiofrequency transmitted by the RF coil assembly needs to match the main magnetic field in order to receive a clear signal, low noise and sharper images. The variability in the magnetic field can be compensated by tuning the frequency of the electromagnetic radiation transmitted by the RF coils. However, tuning of the RF coils is currently done manually by mechanically adjusting the location of the RF coils with respect to the magnetic field, and thus causing a change in the RF field. Such manual systems involve trial and error and are prone to elaborate and lengthy calibrations.
None of the above provides a simple solution for routine insertion of more than one maneuverable small and tangible objects, such as laboratory items (microplates laboratory animals etc), within a single lab-scale experimental MRI device. Hence an MRI device with a plurality of individually controllable entry ports and MRI-compatible inserts therefor fulfill a long felt need. Moreover, introducing an automated RF coil tuning system to the RF coil animal holding system, provided to automatically match the induced RF field to the main magnetic field, would also fulfill a long felt need.